Australian Amphipoda: Melitidae

J.K. Lowry, P.B. Berents and R.T. Springthorpe
Division of Invertebrate Zoology
The Australian Museum
6 College Street, Sydney, NSW 2010, Australia
Phone: 612 9320 6260
Fax: 612 9320 6050

Email: jimlowry@crustacea.net
pennyberents@crustacea.net
Email Roger Springthorpe

The Australian Melitidae is a large group of about 66 species in 16 mostly homogeneous genera. The main references for this group are J.L. Barnard (1972a; 1974) who described 16 species and redescribed several more and Berents (1983) who described seven species from the Great Barrier Reef and documented several others. Although Haswell (1879) described nine species from the Port Jackson area, these have all been redescribed later. In this review six additional species are recorded which will be formally described later (Lowry & Springthorpe, in prep.).

Five of the genera and 12 of the species are strictly freshwater and are not included in this monograph. A dichotomous key to these species can be found in Bradbury & Williams (1997).

About 17 of the 52 known marine species (30 %) recorded from Australian waters also have extrinsic distributions, mainly in the Indo West Pacific -. The main genera with wide-spread distributions are Elasmopus and Maera, each with four species and Ceradocus and Melita, each with two species. About one third of these species are distributed between Australia and New Zealand, but the other two thirds have wider distributions within the Indo West Pacific.

The best taxonomic coverage within Australia of melitid species is along the east and west coasts. In the north-east, south-east and south-west, each area has between 15 and 20 reported species. There are 33 species known along the east coast and about 18 species known along the west coast of Australia. Although there are only eight species reported from the south it is probable that it shares species, with the south-eastern and south-western geographic areas. The north-western (6 species) and particularly northern (1 species) areas of Australia are very poorly known.

Melitids are mainly shallow water amphipods often living on hard bottoms or wharf pilings among algae, beds of tunicates or mussel beds. In tropical areas they are common in coral rubble.

Tattersall (1922) recorded Ceradocus rubromaculatus from the Abrohlos Islands, Western Australia. Ledoyer (1982) suggested that Tattersall's (1922) material belonged to a Malagasy species, which he named C. tattersalli. We have examined the description and figures and of both authors. Based on his description and illustrations we think that Tattersall had at least two species in his collections and maybe three. The description of the large female (10 mm) indicates that it belonged in the genus Ceradocus. The description of the large male indicates that it could belong in Elasmopus, Maera or Ceradocus. The illustrations of the male gnathopods are similar to those of Ceradoucs woorree Berents, 1983, but in Tattersall's material the larger gnathopod 2 has a sinusoidal palmar margin (C. woorree has a convex margin) and the smaller gnathopod 2 has a straight palmar margin (C. woorree has a convex margin).

At least three species of Dulichiella have been reported from Australian waters. Two of these species have wide-spread distributions and one is considered to be an Australian endemic, but all are currently confused. We are currently studying the Australian Dulichiella problem and as soon as we have a solution we will place the results online

The original description of Maera boeckii Haswell, 1879, was inadequate and the type material is apparently lost. As a result the species has been unidentifiable. Sheard (1937) placed it in his catalogue of Australian Gammaridea under the name Elasmopus boeckii. Since that time there have been no further records and there has never been new material. While studying collections for the Australian Amphipod Project, we descovered material from Port Jackson which we are referring to this species.

The name Maera hamigera Haswell, 1879, (type locality: Port Jackson) has not been used for a species living in Australian waters since Stebbing (1910a), but it has been used for species living in the Red Sea (Walker, 1909), southern Africa (K.H. Barnard, 1916), Micronesia (J.L. Barnard, 1965), the Mediterranean Sea (Karaman & Ruffo, 1971), Madagascar (Ledoyer, 1982) and Western Samoa (Myers, 1997). In the Australian Museum collections, a slide from the syntype series shows the unusual gnathopod 2 of this species. In collections from Twofold Bay, on the south coast of New South Wales, we discovered many specimens of this unusual species. Based on these results M. hamigera is confined to south-eastern Australia.

Stebbing (1910a: 599) reported the Mediterranean Sea species, Maera inaequipes, from off Coogee and Wollongong. He did not illustrate the material and the specimens are no long extant. Except for Hale's (1929) misidentification of Maera viridis as Maera inaequipes, this is the only record of M. inaequipes from Australian waters and we consider it as a dubious record.

The original description of Mallacoota subcarinata (Haswell, 1879b) was apparently based on a series of large adult specimens from Port Jackson. These specimens are lodged in the Australian Museum, but are in poor condition. All have the unusual gnathopod 2 palmar shape indicated by Haswell's (1879b) illustrations. Unfortunatly this is not one of the species with which the name has been subsequently associated. Myers (1985) summarised this problem and concluded that an in-depth study using a wide range of material was needed to solve it. We are currently: re-establishing the species concept of M. subcarinata, by redescribing and illustrating the original type material; describing other Australian species, plus ones which have, in the past, been mis-identified as M. subcarianta; and preparing comments on records of M. subcarinata from geographic areas outside of Australia. As soon as this is done we will place the results online.

At the moment species of Dulichiella, Hoho and most species of Mallacoota are not included in this database.

Users, particularly of the interactive key, should be aware that the possibilty of undescribed taxa appearing in samples, particularly from northern Australia, is high.

The following abbreviations are used on the plates: A, antenna; C, coxa; E, epistome; EP, epimeron; G, gnathopod; H, head; MD, mandible; MP, maxilliped; MX, maxilla; OP, outer plate; P, peraeopod; p, palp; T, telson; U, uropod; UR, urosomite.

This publication should be cited as : Lowry, J.K., P.B. Berents & R.T. Springthorpe, 2001. Australian Amphipoda: Melitidae. Version 1: 18 January 2001. https://crustacea.net/.